/* * Common framework for low-level network console, dump, and debugger code * * Sep 8 2003 Matt Mackall <mpm@selenic.com> * * based on the netconsole code from: * * Copyright (C) 2001 Ingo Molnar <mingo@redhat.com> * Copyright (C) 2002 Red Hat, Inc. */ #include <linux/smp_lock.h>#include <linux/netdevice.h>#include <linux/etherdevice.h>#include <linux/string.h>#include <linux/if_arp.h>#include <linux/inetdevice.h>#include <linux/inet.h>#include <linux/interrupt.h>#include <linux/netpoll.h>#include <linux/sched.h>#include <linux/delay.h>#include <linux/rcupdate.h>#include <linux/workqueue.h>#include <net/tcp.h>#include <net/udp.h>#include <asm/unaligned.h> /* * We maintain a small pool of fully-sized skbs, to make sure the * message gets out even in extreme OOM situations. */ #define MAX_UDP_CHUNK 1460#define MAX_SKBS 32#define MAX_QUEUE_DEPTH (MAX_SKBS / 2) static struct sk_buff_head skb_pool; static atomic_t trapped; #define USEC_PER_POLL 50#define NETPOLL_RX_ENABLED 1#define NETPOLL_RX_DROP 2 #define MAX_SKB_SIZE \ (MAX_UDP_CHUNK + sizeof(struct udphdr) + \ sizeof(struct iphdr) + sizeof(struct ethhdr)) static void zap_completion_queue(void);static void arp_reply(struct sk_buff *skb); static void queue_process(struct work_struct *work){ struct netpoll_info *npinfo = container_of(work, struct netpoll_info, tx_work.work); struct sk_buff *skb; unsigned long flags; while ((skb = skb_dequeue(&npinfo->txq))) { struct net_device *dev = skb->dev; if (!netif_device_present(dev) || !netif_running(dev)) { __kfree_skb(skb); continue; } local_irq_save(flags); netif_tx_lock(dev); if (netif_queue_stopped(dev) || dev->hard_start_xmit(skb, dev) != NETDEV_TX_OK) { skb_queue_head(&npinfo->txq, skb); netif_tx_unlock(dev); local_irq_restore(flags); schedule_delayed_work(&npinfo->tx_work, HZ/10); return; } netif_tx_unlock(dev); local_irq_restore(flags); }} static __sum16 checksum_udp(struct sk_buff *skb, struct udphdr *uh, unsigned short ulen, __be32 saddr, __be32 daddr){ __wsum psum; if (uh->check == 0 || skb->ip_summed == CHECKSUM_UNNECESSARY) return 0; psum = csum_tcpudp_nofold(saddr, daddr, ulen, IPPROTO_UDP, 0); if (skb->ip_summed == CHECKSUM_COMPLETE && !csum_fold(csum_add(psum, skb->csum))) return 0; skb->csum = psum; return __skb_checksum_complete(skb);} /* * Check whether delayed processing was scheduled for our NIC. If so, * we attempt to grab the poll lock and use ->poll() to pump the card. * If this fails, either we've recursed in ->poll() or it's already * running on another CPU. * * Note: we don't mask interrupts with this lock because we're using * trylock here and interrupts are already disabled in the softirq * case. Further, we test the poll_owner to avoid recursion on UP * systems where the lock doesn't exist. * * In cases where there is bi-directional communications, reading only * one message at a time can lead to packets being dropped by the * network adapter, forcing superfluous retries and possibly timeouts. * Thus, we set our budget to greater than 1. */static void poll_napi(struct netpoll *np){ struct netpoll_info *npinfo = np->dev->npinfo; int budget = 16; if (test_bit(__LINK_STATE_RX_SCHED, &np->dev->state) && npinfo->poll_owner != smp_processor_id() && spin_trylock(&npinfo->poll_lock)) { npinfo->rx_flags |= NETPOLL_RX_DROP; atomic_inc(&trapped); np->dev->poll(np->dev, &budget); atomic_dec(&trapped); npinfo->rx_flags &= ~NETPOLL_RX_DROP; spin_unlock(&npinfo->poll_lock); }} static void service_arp_queue(struct netpoll_info *npi){ struct sk_buff *skb; if (unlikely(!npi)) return; skb = skb_dequeue(&npi->arp_tx); while (skb != NULL) { arp_reply(skb); skb = skb_dequeue(&npi->arp_tx); }} void netpoll_poll(struct netpoll *np){ if (!np->dev || !netif_running(np->dev) || !np->dev->poll_controller) return; /* Process pending work on NIC */ np->dev->poll_controller(np->dev); if (np->dev->poll) poll_napi(np); service_arp_queue(np->dev->npinfo); zap_completion_queue();} static void refill_skbs(void){ struct sk_buff *skb; unsigned long flags; spin_lock_irqsave(&skb_pool.lock, flags); while (skb_pool.qlen < MAX_SKBS) { skb = alloc_skb(MAX_SKB_SIZE, GFP_ATOMIC); if (!skb) break; __skb_queue_tail(&skb_pool, skb); } spin_unlock_irqrestore(&skb_pool.lock, flags);} static void zap_completion_queue(void){ unsigned long flags; struct softnet_data *sd = &get_cpu_var(softnet_data); if (sd->completion_queue) { struct sk_buff *clist; local_irq_save(flags); clist = sd->completion_queue; sd->completion_queue = NULL; local_irq_restore(flags); while (clist != NULL) { struct sk_buff *skb = clist; clist = clist->next; if (skb->destructor) dev_kfree_skb_any(skb); /* put this one back */ else __kfree_skb(skb); } } put_cpu_var(softnet_data);} static struct sk_buff *find_skb(struct netpoll *np, int len, int reserve){ int count = 0; struct sk_buff *skb; zap_completion_queue(); refill_skbs();repeat: skb = alloc_skb(len, GFP_ATOMIC); if (!skb) skb = skb_dequeue(&skb_pool); if (!skb) { if (++count < 10) { netpoll_poll(np); goto repeat; } return NULL; } atomic_set(&skb->users, 1); skb_reserve(skb, reserve); return skb;} static void netpoll_send_skb(struct netpoll *np, struct sk_buff *skb){ int status = NETDEV_TX_BUSY; unsigned long tries; struct net_device *dev = np->dev; struct netpoll_info *npinfo = np->dev->npinfo; if (!npinfo || !netif_running(dev) || !netif_device_present(dev)) { __kfree_skb(skb); return; } /* don't get messages out of order, and no recursion */ if (skb_queue_len(&npinfo->txq) == 0 && npinfo->poll_owner != smp_processor_id()) { unsigned long flags; local_irq_save(flags); if (netif_tx_trylock(dev)) { /* try until next clock tick */ for (tries = jiffies_to_usecs(1)/USEC_PER_POLL; tries > 0; --tries) { if (!netif_queue_stopped(dev)) status = dev->hard_start_xmit(skb, dev); if (status == NETDEV_TX_OK) break; /* tickle device maybe there is some cleanup */ netpoll_poll(np); udelay(USEC_PER_POLL); } netif_tx_unlock(dev); } local_irq_restore(flags); } if (status != NETDEV_TX_OK) { skb_queue_tail(&npinfo->txq, skb); schedule_delayed_work(&npinfo->tx_work,0); }} void netpoll_send_udp(struct netpoll *np, const char *msg, int len){ int total_len, eth_len, ip_len, udp_len; struct sk_buff *skb; struct udphdr *udph; struct iphdr *iph; struct ethhdr *eth; udp_len = len + sizeof(*udph); ip_len = eth_len = udp_len + sizeof(*iph); total_len = eth_len + ETH_HLEN + NET_IP_ALIGN; skb = find_skb(np, total_len, total_len - len); if (!skb) return; memcpy(skb->data, msg, len); skb->len += len; skb->h.uh = udph = (struct udphdr *) skb_push(skb, sizeof(*udph)); udph->source = htons(np->local_port); udph->dest = htons(np->remote_port); udph->len = htons(udp_len); udph->check = 0; udph->check = csum_tcpudp_magic(htonl(np->local_ip), htonl(np->remote_ip), udp_len, IPPROTO_UDP, csum_partial((unsigned char *)udph, udp_len, 0)); if (udph->check == 0) udph->check = CSUM_MANGLED_0; skb->nh.iph = iph = (struct iphdr *)skb_push(skb, sizeof(*iph)); /* iph->version = 4; iph->ihl = 5; */ put_unaligned(0x45, (unsigned char *)iph); iph->tos = 0; put_unaligned(htons(ip_len), &(iph->tot_len)); iph->id = 0; iph->frag_off = 0; iph->ttl = 64; iph->protocol = IPPROTO_UDP; iph->check = 0; put_unaligned(htonl(np->local_ip), &(iph->saddr)); put_unaligned(htonl(np->remote_ip), &(iph->daddr)); iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl); eth = (struct ethhdr *) skb_push(skb, ETH_HLEN); skb->mac.raw = skb->data; skb->protocol = eth->h_proto = htons(ETH_P_IP); memcpy(eth->h_source, np->local_mac, 6); memcpy(eth->h_dest, np->remote_mac, 6); skb->dev = np->dev; netpoll_send_skb(np, skb);} static void arp_reply(struct sk_buff *skb){ struct netpoll_info *npinfo = skb->dev->npinfo; struct arphdr *arp; unsigned char *arp_ptr; int size, type = ARPOP_REPLY, ptype = ETH_P_ARP; __be32 sip, tip; unsigned char *sha; struct sk_buff *send_skb; struct netpoll *np = NULL; if (npinfo->rx_np && npinfo->rx_np->dev == skb->dev) np = npinfo->rx_np; if (!np) return; /* No arp on this interface */ if (skb->dev->flags & IFF_NOARP) return; if (!pskb_may_pull(skb, (sizeof(struct arphdr) + (2 * skb->dev->addr_len) + (2 * sizeof(u32))))) return; skb->h.raw = skb->nh.raw = skb->data; arp = skb->nh.arph; if ((arp->ar_hrd != htons(ARPHRD_ETHER) && arp->ar_hrd != htons(ARPHRD_IEEE802)) || arp->ar_pro != htons(ETH_P_IP) || arp->ar_op != htons(ARPOP_REQUEST)) return; arp_ptr = (unsigned char *)(arp+1); /* save the location of the src hw addr */ sha = arp_ptr; arp_ptr += skb->dev->addr_len; memcpy(&sip, arp_ptr, 4); arp_ptr += 4; /* if we actually cared about dst hw addr, it would get copied here */ arp_ptr += skb->dev->addr_len; memcpy(&tip, arp_ptr, 4); /* Should we ignore arp? */ if (tip != htonl(np->local_ip) || LOOPBACK(tip) || MULTICAST(tip)) return; size = sizeof(struct arphdr) + 2 * (skb->dev->addr_len + 4); send_skb = find_skb(np, size + LL_RESERVED_SPACE(np->dev), LL_RESERVED_SPACE(np->dev)); if (!send_skb) return; send_skb->nh.raw = send_skb->data; arp = (struct arphdr *) skb_put(send_skb, size); send_skb->dev = skb->dev; send_skb->protocol = htons(ETH_P_ARP); /* Fill the device header for the ARP frame */ if (np->dev->hard_header && np->dev->hard_header(send_skb, skb->dev, ptype, sha, np->local_mac, send_skb->len) < 0) { kfree_skb(send_skb); return; } /* * Fill out the arp protocol part. * * we only support ethernet device type, * which (according to RFC 1390) should always equal 1 (Ethernet). */ arp->ar_hrd = htons(np->dev->type); arp->ar_pro = htons(ETH_P_IP); arp->ar_hln = np->dev->addr_len; arp->ar_pln = 4; arp->ar_op = htons(type); arp_ptr=(unsigned char *)(arp + 1); memcpy(arp_ptr, np->dev->dev_addr, np->dev->addr_len); arp_ptr += np->dev->addr_len; memcpy(arp_ptr, &tip, 4); arp_ptr += 4; memcpy(arp_ptr, sha, np->dev->addr_len); arp_ptr += np->dev->addr_len; memcpy(arp_ptr, &sip, 4); netpoll_send_skb(np, send_skb);} int __netpoll_rx(struct sk_buff *skb){ int proto, len, ulen; struct iphdr *iph; struct udphdr *uh; struct netpoll_info *npi = skb->dev->npinfo; struct netpoll *np = npi->rx_np; if (!np) goto out; if (skb->dev->type != ARPHRD_ETHER) goto out; /* check if netpoll clients need ARP */ if (skb->protocol == __constant_htons(ETH_P_ARP) && atomic_read(&trapped)) { skb_queue_tail(&npi->arp_tx, skb); return 1; } proto = ntohs(eth_hdr(skb)->h_proto); if (proto != ETH_P_IP) goto out; if (skb->pkt_type == PACKET_OTHERHOST) goto out; if (skb_shared(skb)) goto out; iph = (struct iphdr *)skb->data; if (!pskb_may_pull(skb, sizeof(struct iphdr))) goto out; if (iph->ihl < 5 || iph->version != 4) goto out; if (!pskb_may_pull(skb, iph->ihl*4)) goto out; if (ip_fast_csum((u8 *)iph, iph->ihl) != 0) goto out; len = ntohs(iph->tot_len); if (skb->len < len || len < iph->ihl*4) goto out; /* * Our transport medium may have padded the buffer out. * Now We trim to the true length of the frame. */ if (pskb_trim_rcsum(skb, len)) goto out; if (iph->protocol != IPPROTO_UDP) goto out; len -= iph->ihl*4; uh = (struct udphdr *)(((char *)iph) + iph->ihl*4); ulen = ntohs(uh->len); if (ulen != len) goto out; if (checksum_udp(skb, uh, ulen, iph->saddr, iph->daddr)) goto out; if (np->local_ip && np->local_ip != ntohl(iph->daddr)) goto out; if (np->remote_ip && np->remote_ip != ntohl(iph->saddr)) goto out; if (np->local_port && np->local_port != ntohs(uh->dest)) goto out; np->rx_hook(np, ntohs(uh->source), (char *)(uh+1),Lines 1–500 of 815. 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/* * Common framework for low-level network console, dump, and debugger code * * Sep 8 2003 Matt Mackall <mpm@selenic.com> * * based on the netconsole code from: * * Copyright (C) 2001 Ingo Molnar <mingo@redhat.com> * Copyright (C) 2002 Red Hat, Inc. */ #include <linux/smp_lock.h> #include <linux/netdevice.h> #include <linux/etherdevice.h> #include <linux/string.h> #include <linux/if_arp.h> #include <linux/inetdevice.h> #include <linux/inet.h> #include <linux/interrupt.h> #include <linux/netpoll.h> #include <linux/sched.h> #include <linux/delay.h> #include <linux/rcupdate.h> #include <linux/workqueue.h> #include <net/tcp.h> #include <net/udp.h> #include <asm/unaligned.h> /* * We maintain a small pool of fully-sized skbs, to make sure the * message gets out even in extreme OOM situations. */ #define MAX_UDP_CHUNK 1460 #define MAX_SKBS 32 #define MAX_QUEUE_DEPTH (MAX_SKBS / 2) static struct sk_buff_head skb_pool; static atomic_t trapped; #define USEC_PER_POLL 50 #define NETPOLL_RX_ENABLED 1 #define NETPOLL_RX_DROP 2 #define MAX_SKB_SIZE \ (MAX_UDP_CHUNK + sizeof(struct udphdr) + \ sizeof(struct iphdr) + sizeof(struct ethhdr)) static void zap_completion_queue(void); static void arp_reply(struct sk_buff *skb); static void queue_process(struct work_struct *work) { struct netpoll_info *npinfo = container_of(work, struct netpoll_info, tx_work.work); struct sk_buff *skb; unsigned long flags; while ((skb = skb_dequeue(&npinfo->txq))) { struct net_device *dev = skb->dev; if (!netif_device_present(dev) || !netif_running(dev)) { __kfree_skb(skb); continue; } local_irq_save(flags); netif_tx_lock(dev); if (netif_queue_stopped(dev) || dev->hard_start_xmit(skb, dev) != NETDEV_TX_OK) { skb_queue_head(&npinfo->txq, skb); netif_tx_unlock(dev); local_irq_restore(flags); schedule_delayed_work(&npinfo->tx_work, HZ/10); return; } netif_tx_unlock(dev); local_irq_restore(flags); } } static __sum16 checksum_udp(struct sk_buff *skb, struct udphdr *uh, unsigned short ulen, __be32 saddr, __be32 daddr) { __wsum psum; if (uh->check == 0 || skb->ip_summed == CHECKSUM_UNNECESSARY) return 0; psum = csum_tcpudp_nofold(saddr, daddr, ulen, IPPROTO_UDP, 0); if (skb->ip_summed == CHECKSUM_COMPLETE && !csum_fold(csum_add(psum, skb->csum))) return 0; skb->csum = psum; return __skb_checksum_complete(skb); } /* * Check whether delayed processing was scheduled for our NIC. If so, * we attempt to grab the poll lock and use ->poll() to pump the card. * If this fails, either we've recursed in ->poll() or it's already * running on another CPU. * * Note: we don't mask interrupts with this lock because we're using * trylock here and interrupts are already disabled in the softirq * case. Further, we test the poll_owner to avoid recursion on UP * systems where the lock doesn't exist. * * In cases where there is bi-directional communications, reading only * one message at a time can lead to packets being dropped by the * network adapter, forcing superfluous retries and possibly timeouts. * Thus, we set our budget to greater than 1. */ static void poll_napi(struct netpoll *np) { struct netpoll_info *npinfo = np->dev->npinfo; int budget = 16; if (test_bit(__LINK_STATE_RX_SCHED, &np->dev->state) && npinfo->poll_owner != smp_processor_id() && spin_trylock(&npinfo->poll_lock)) { npinfo->rx_flags |= NETPOLL_RX_DROP; atomic_inc(&trapped); np->dev->poll(np->dev, &budget); atomic_dec(&trapped); npinfo->rx_flags &= ~NETPOLL_RX_DROP; spin_unlock(&npinfo->poll_lock); } } static void service_arp_queue(struct netpoll_info *npi) { struct sk_buff *skb; if (unlikely(!npi)) return; skb = skb_dequeue(&npi->arp_tx); while (skb != NULL) { arp_reply(skb); skb = skb_dequeue(&npi->arp_tx); } } void netpoll_poll(struct netpoll *np) { if (!np->dev || !netif_running(np->dev) || !np->dev->poll_controller) return; /* Process pending work on NIC */ np->dev->poll_controller(np->dev); if (np->dev->poll) poll_napi(np); service_arp_queue(np->dev->npinfo); zap_completion_queue(); } static void refill_skbs(void) { struct sk_buff *skb; unsigned long flags; spin_lock_irqsave(&skb_pool.lock, flags); while (skb_pool.qlen < MAX_SKBS) { skb = alloc_skb(MAX_SKB_SIZE, GFP_ATOMIC); if (!skb) break; __skb_queue_tail(&skb_pool, skb); } spin_unlock_irqrestore(&skb_pool.lock, flags); } static void zap_completion_queue(void) { unsigned long flags; struct softnet_data *sd = &get_cpu_var(softnet_data); if (sd->completion_queue) { struct sk_buff *clist; local_irq_save(flags); clist = sd->completion_queue; sd->completion_queue = NULL; local_irq_restore(flags); while (clist != NULL) { struct sk_buff *skb = clist; clist = clist->next; if (skb->destructor) dev_kfree_skb_any(skb); /* put this one back */ else __kfree_skb(skb); } } put_cpu_var(softnet_data); } static struct sk_buff *find_skb(struct netpoll *np, int len, int reserve) { int count = 0; struct sk_buff *skb; zap_completion_queue(); refill_skbs(); repeat: skb = alloc_skb(len, GFP_ATOMIC); if (!skb) skb = skb_dequeue(&skb_pool); if (!skb) { if (++count < 10) { netpoll_poll(np); goto repeat; } return NULL; } atomic_set(&skb->users, 1); skb_reserve(skb, reserve); return skb; } static void netpoll_send_skb(struct netpoll *np, struct sk_buff *skb) { int status = NETDEV_TX_BUSY; unsigned long tries; struct net_device *dev = np->dev; struct netpoll_info *npinfo = np->dev->npinfo; if (!npinfo || !netif_running(dev) || !netif_device_present(dev)) { __kfree_skb(skb); return; } /* don't get messages out of order, and no recursion */ if (skb_queue_len(&npinfo->txq) == 0 && npinfo->poll_owner != smp_processor_id()) { unsigned long flags; local_irq_save(flags); if (netif_tx_trylock(dev)) { /* try until next clock tick */ for (tries = jiffies_to_usecs(1)/USEC_PER_POLL; tries > 0; --tries) { if (!netif_queue_stopped(dev)) status = dev->hard_start_xmit(skb, dev); if (status == NETDEV_TX_OK) break; /* tickle device maybe there is some cleanup */ netpoll_poll(np); udelay(USEC_PER_POLL); } netif_tx_unlock(dev); } local_irq_restore(flags); } if (status != NETDEV_TX_OK) { skb_queue_tail(&npinfo->txq, skb); schedule_delayed_work(&npinfo->tx_work,0); } } void netpoll_send_udp(struct netpoll *np, const char *msg, int len) { int total_len, eth_len, ip_len, udp_len; struct sk_buff *skb; struct udphdr *udph; struct iphdr *iph; struct ethhdr *eth; udp_len = len + sizeof(*udph); ip_len = eth_len = udp_len + sizeof(*iph); total_len = eth_len + ETH_HLEN + NET_IP_ALIGN; skb = find_skb(np, total_len, total_len - len); if (!skb) return; memcpy(skb->data, msg, len); skb->len += len; skb->h.uh = udph = (struct udphdr *) skb_push(skb, sizeof(*udph)); udph->source = htons(np->local_port); udph->dest = htons(np->remote_port); udph->len = htons(udp_len); udph->check = 0; udph->check = csum_tcpudp_magic(htonl(np->local_ip), htonl(np->remote_ip), udp_len, IPPROTO_UDP, csum_partial((unsigned char *)udph, udp_len, 0)); if (udph->check == 0) udph->check = CSUM_MANGLED_0; skb->nh.iph = iph = (struct iphdr *)skb_push(skb, sizeof(*iph)); /* iph->version = 4; iph->ihl = 5; */ put_unaligned(0x45, (unsigned char *)iph); iph->tos = 0; put_unaligned(htons(ip_len), &(iph->tot_len)); iph->id = 0; iph->frag_off = 0; iph->ttl = 64; iph->protocol = IPPROTO_UDP; iph->check = 0; put_unaligned(htonl(np->local_ip), &(iph->saddr)); put_unaligned(htonl(np->remote_ip), &(iph->daddr)); iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl); eth = (struct ethhdr *) skb_push(skb, ETH_HLEN); skb->mac.raw = skb->data; skb->protocol = eth->h_proto = htons(ETH_P_IP); memcpy(eth->h_source, np->local_mac, 6); memcpy(eth->h_dest, np->remote_mac, 6); skb->dev = np->dev; netpoll_send_skb(np, skb); } static void arp_reply(struct sk_buff *skb) { struct netpoll_info *npinfo = skb->dev->npinfo; struct arphdr *arp; unsigned char *arp_ptr; int size, type = ARPOP_REPLY, ptype = ETH_P_ARP; __be32 sip, tip; unsigned char *sha; struct sk_buff *send_skb; struct netpoll *np = NULL; if (npinfo->rx_np && npinfo->rx_np->dev == skb->dev) np = npinfo->rx_np; if (!np) return; /* No arp on this interface */ if (skb->dev->flags & IFF_NOARP) return; if (!pskb_may_pull(skb, (sizeof(struct arphdr) + (2 * skb->dev->addr_len) + (2 * sizeof(u32))))) return; skb->h.raw = skb->nh.raw = skb->data; arp = skb->nh.arph; if ((arp->ar_hrd != htons(ARPHRD_ETHER) && arp->ar_hrd != htons(ARPHRD_IEEE802)) || arp->ar_pro != htons(ETH_P_IP) || arp->ar_op != htons(ARPOP_REQUEST)) return; arp_ptr = (unsigned char *)(arp+1); /* save the location of the src hw addr */ sha = arp_ptr; arp_ptr += skb->dev->addr_len; memcpy(&sip, arp_ptr, 4); arp_ptr += 4; /* if we actually cared about dst hw addr, it would get copied here */ arp_ptr += skb->dev->addr_len; memcpy(&tip, arp_ptr, 4); /* Should we ignore arp? */ if (tip != htonl(np->local_ip) || LOOPBACK(tip) || MULTICAST(tip)) return; size = sizeof(struct arphdr) + 2 * (skb->dev->addr_len + 4); send_skb = find_skb(np, size + LL_RESERVED_SPACE(np->dev), LL_RESERVED_SPACE(np->dev)); if (!send_skb) return; send_skb->nh.raw = send_skb->data; arp = (struct arphdr *) skb_put(send_skb, size); send_skb->dev = skb->dev; send_skb->protocol = htons(ETH_P_ARP); /* Fill the device header for the ARP frame */ if (np->dev->hard_header && np->dev->hard_header(send_skb, skb->dev, ptype, sha, np->local_mac, send_skb->len) < 0) { kfree_skb(send_skb); return; } /* * Fill out the arp protocol part. * * we only support ethernet device type, * which (according to RFC 1390) should always equal 1 (Ethernet). */ arp->ar_hrd = htons(np->dev->type); arp->ar_pro = htons(ETH_P_IP); arp->ar_hln = np->dev->addr_len; arp->ar_pln = 4; arp->ar_op = htons(type); arp_ptr=(unsigned char *)(arp + 1); memcpy(arp_ptr, np->dev->dev_addr, np->dev->addr_len); arp_ptr += np->dev->addr_len; memcpy(arp_ptr, &tip, 4); arp_ptr += 4; memcpy(arp_ptr, sha, np->dev->addr_len); arp_ptr += np->dev->addr_len; memcpy(arp_ptr, &sip, 4); netpoll_send_skb(np, send_skb); } int __netpoll_rx(struct sk_buff *skb) { int proto, len, ulen; struct iphdr *iph; struct udphdr *uh; struct netpoll_info *npi = skb->dev->npinfo; struct netpoll *np = npi->rx_np; if (!np) goto out; if (skb->dev->type != ARPHRD_ETHER) goto out; /* check if netpoll clients need ARP */ if (skb->protocol == __constant_htons(ETH_P_ARP) && atomic_read(&trapped)) { skb_queue_tail(&npi->arp_tx, skb); return 1; } proto = ntohs(eth_hdr(skb)->h_proto); if (proto != ETH_P_IP) goto out; if (skb->pkt_type == PACKET_OTHERHOST) goto out; if (skb_shared(skb)) goto out; iph = (struct iphdr *)skb->data; if (!pskb_may_pull(skb, sizeof(struct iphdr))) goto out; if (iph->ihl < 5 || iph->version != 4) goto out; if (!pskb_may_pull(skb, iph->ihl*4)) goto out; if (ip_fast_csum((u8 *)iph, iph->ihl) != 0) goto out; len = ntohs(iph->tot_len); if (skb->len < len || len < iph->ihl*4) goto out; /* * Our transport medium may have padded the buffer out. * Now We trim to the true length of the frame. */ if (pskb_trim_rcsum(skb, len)) goto out; if (iph->protocol != IPPROTO_UDP) goto out; len -= iph->ihl*4; uh = (struct udphdr *)(((char *)iph) + iph->ihl*4); ulen = ntohs(uh->len); if (ulen != len) goto out; if (checksum_udp(skb, uh, ulen, iph->saddr, iph->daddr)) goto out; if (np->local_ip && np->local_ip != ntohl(iph->daddr)) goto out; if (np->remote_ip && np->remote_ip != ntohl(iph->saddr)) goto out; if (np->local_port && np->local_port != ntohs(uh->dest)) goto out; np->rx_hook(np, ntohs(uh->source), (char *)(uh+1),